The Argentine emerged from the bench in the 73rd minute to replace Jeremy Menez, and after sporadic attacking activity, departed in the 80th minute in favour of Javier Pastore.

Four minutes later, James Rodriguez put the hosts in front with a superb finish to claim victory over a distinctly average PSG side, who were outplayed by their Portuguese hosts.

Lavezzi's substitution brought about a furious reaction from the former Napoli forward, who unleashed his anger on a drinks cooler on the touch-line, spreading rumours of a rift between player and coach, but Ancelotti brushed off such suggestions.

"Lavezzi? He had some muscular discomforts. He was not able to continue, so I took him off," explained the 53-year-old to Sky Sport Italia.

"The game was complicated, but we had several opportunities, we counterattacked. It was not a bad match, but perhaps we paid them a bit too much respect. We can do better than this.

"These are new experiences for many players, so there is always the danger to have setbacks. There is still much to play for, [it is] nothing dramatic."

Captain for the evening, Mamadou Sakho insisted that the defeat was a minor setback, and that the club will recover ahead of their next game.

"We did not create many chances, and Porto played well. But we are very disappointed because we wanted to play a great game tonight," the 22-year-old told reporters after the game.

"There is no need to worry though. This is nothing dramatic, because there are a lot of games. For OM [PSG's next game], we will recover well and be mentally prepared."

Les Parisiens' next game is against fierce rivals Olympique de Marseille in the Derby de France. Kick-off at Stade Velodrome on Sunday is at 21:00CET.